PRIMA-1Met, also called APR-246, is converted to methylene quinuclidinone (MQ), a Michael acceptor. It interacts with p53 through the cysteine (Cys) residue. It blocks the thioredoxin reductase (TrxR1) enzyme. It is under clinical investigation and well-studied. PRIMA-1Met effect is tested on breast cancer specific gene expression.
PRIMA-1Met (APR-246) is a re-activator of mutant p53 activity. It′s the methylated, more potent derivative of PRIMA-1. PRIMA-1Met covalently modifies the core domain of mutated p53 restoring the wild-type conformation and activty of p53 in tumor cells, leading to cell cycle arrest and apoptosis. PRIMA-1Met has also been shown to increase intracellular levels of reactive oxygen species (ROS), which may contribute to its anti-tumor activity.